External fixator

Abstract

The invention relates to an external fixator device and the method of its use in treating bone fractures and in orthopedic interventions, such as corrective osteotomies.

The invention claimed is: 
     
       1. An external fixator for fixing bone segments into a construct comprising:
 a frame ( 1 ) consisting of a first bar and a second bar ( 1   a ,  1   b ), wherein the first bar and the second bar are opposed to each other in a clamshell fashion and clamped together by a plurality of fasteners; and 
 a plurality of bone pins ( 2 ) interposed between the first bar and the second bar, wherein the clamping of the first bar and the second bar results in clamping of a subset of the plurality of bone pins interposed between the bars, wherein the plurality of bone pins are at a multitude of pre-set positions, and wherein at least one unclamped bone pin of the plurality of bone pins is effectively clamped by insertion of one or more fixing elements on a surface of the at least one unclamped bone pin of the plurality of bone pins disposed between the first bar and the second bar. 
 
     
     
       2. The external fixator of  claim 1 , wherein the plurality of bone pins ( 2 ) can be inserted through the frame ( 1 ) between the first bar and the second bar at pre-defined positions, wherein the pre-defined positions comprise at least two different angulations with respect to the frame ( 1 ). 
     
     
       3. The external fixator of  claim 2 , wherein the pre-defined positions include (i) a first plurality of grooves perpendicular to a longitudinal axis of the frame and (ii) a second plurality of grooves at an oblique angle to the longitudinal axis of the frame, and wherein each of the second plurality of grooves has a depth which varies along a width of the frame. 
     
     
       4. The external fixator of  claim 2 , wherein the pre-defined positions include a first position at a first oblique angle to the longitudinal axis of the frame and a second position at a second oblique angle to the longitudinal axis of the frame, wherein the first position is substantially perpendicular to the second position. 
     
     
       5. The external fixator of  claim 1 , wherein the clamped subset of the plurality of bone pins are disposed between the first bar and the second bar at an angle perpendicular to the longitudinal axis of the frame, and
 wherein the at least one unclamped bone pin of the plurality of bone pins disposed between the first bar and the second bar at an oblique angle to the longitudinal axis of the frame remains unclamped. 
 
     
     
       6. The external fixator of  claim 1 , wherein each of the plurality of bone pins ( 2 ) interposed between the first bar and the second bar is located in at least one of: (i) a mid-plane of the frame, (ii) a first plane transverse to the mid-plane of the frame, and/or (iii) a second plane transverse to the mid-plane of the frame. 
     
     
       7. The external fixator of  claim 1 , wherein the first bar and the second bar ( 1   a ,  1   b ) are injection molded bars comprising a glass fiber or a carbon fiber reinforced polymer. 
     
     
       8. The external fixator of  claim 7 , wherein the first bar and the second bar ( 1   a ,  1   b ) are identical. 
     
     
       9. The external fixator of  claim 1 , wherein the plurality of fasteners comprises bolts and nuts ( 3 ). 
     
     
       10. The external fixator of  claim 1 , wherein the one or more fixing elements are shims ( 14 ). 
     
     
       11. An external fixator for fixing bone segments into a construct comprising:
 a frame ( 1 ) consisting of a first bar and a second bar ( 1   a ,  1   b ), wherein the first bar and the second bar are opposed to each other in a clamshell fashion and clamped together by a plurality of fasteners; and 
 a plurality of bone pins ( 2 ) interposed between the first bar and the second bar, wherein the clamping of the first bar and the second bar results in clamping of a subset of the plurality of bone pins interposed between the bars, wherein the plurality of bone pins are at a multitude of pre-set positions, wherein the plurality of bone pins ( 2 ) can be inserted through the frame ( 1 ) between the first bar and the second bar at pre-defined positions, wherein the pre-defined positions comprise at least two different angulations with respect to the frame ( 1 ), wherein the pre-defined positions include (i) a first plurality of grooves perpendicular to a longitudinal axis of the frame and (ii) a second plurality of grooves at an oblique angle to the longitudinal axis of the frame, and wherein each of the second plurality of grooves has a depth which varies along a width of the frame.